System, device, and method for moisture and texture detection and control in tortilla chip production

ABSTRACT

A production system for moisture and texture detection and control in tortilla and tortilla chip production includes a production line, including a cooker/grinder, a sheeter/cutter, an oven, an equalizer, a fryer, and a cooler/packaging machine; and a production control unit, including a processor, non-transitory memory, an input/output component, a moisture controller, a temperature controller, a belt speed controller, a masa moisture sensor, a chip moisture sensor, laser sensors for measuring surface texture of baked and fried chips, a laser controller, a texture classifier, a feedback controller. Also disclosed is a method for production control, including controlling moisture content, measuring masa moisture, controlling oven, measuring baked surfaces, measuring fried surfaces, classifying baked surfaces, classifying fried surfaces, optimizing oven temperature, optimizing oven belt speed, storing and characterizing historical records.

CROSS-REFERENCE TO RELATED APPLICATIONS

N/A

FIELD OF THE INVENTION

The present invention relates generally to the field of tortillaproduction, and more particularly to methods and systems for controllingmoisture and texture during baking of tortillas, tortilla chips, andother food products.

BACKGROUND OF THE INVENTION

A variety of standardized designs have been developed for productionlines used in industrial food production of tortillas and tortillachips. Well known methods are used to measure and control moisturecontent of masa used for forming chips, but there are generally nomethods for measuring moisture in later stages of production, afterbaking and frying of tortilla chips, and there are no methods formeasuring and controlling surface texture of the finished product.

Thus, despite development in design of production lines, it remains verydifficult to control the moisture and texture of finished tortilla andtortilla chip products.

As such, considering the foregoing, it may be appreciated that therecontinues to be a need for novel and improved devices and methods forcontrolling moisture and texture during baking and frying of tortillasand tortilla chips, and other food products.

SUMMARY OF THE INVENTION

The foregoing needs are met, to a great extent, by the presentinvention, wherein in aspects of this invention, enhancements areprovided to the existing models for controlling texture and moisture intortilla and tortilla chip production.

In an aspect, a production system for moisture and texture detection andcontrol in tortilla chip production, can include:

-   -   a) a production line, including an oven, which is configured to        receive pieces of masa from a sheeter/cutter, via a sheeter        conveyer, such that the pieces pass through the oven on an        internal conveyer, such that the pieces are baked when passing        through the oven; and    -   b) a production control unit, which is configured to control        components of the production line, such that the production        control unit includes:        -   a chip moisture sensor, which is configured to measure a            moisture content of the baked pieces that are emitted from            the oven; and        -   a laser sensor, which is configured to measure a surface            height of the fried pieces that are emitted from the fryer,            such that the laser sensor obtains a continuous sequence of            height measurements at a predetermined measuring rate.

In a related aspect,

-   -   a) the production line can further include an equalizer, which        is configured to receive the baked pieces from the oven, via an        oven conveyer, such that the equalizer is configured to cool the        baked pieces; and a fryer, which is configured to receive the        baked pieces from the equalizer, via an equalizer conveyer, such        that the fryer is configured to fry the cooled baked pieces; and    -   b) the production control unit can further include: a laser        sensor, which is configured to measure a surface height of the        fried pieces that are emitted from the fryer, such that the        laser sensor obtains a continuous sequence of height        measurements at a predetermined measuring rate.

In a related aspect, the production control unit can further include:

-   -   a) a processor;    -   b) a non-transitory memory;    -   c) an input/output component;    -   d) a moisture controller, which is configured to control        moisture content of masa in the cooker/grinder by adjusting a        proportion of water in the mixture of raw corn, water, and        food-grade lime that is processed by the cooker/grinder;    -   e) a temperature controller, which is configured to communicate        with the oven to control a temperature profile of the oven; and    -   f) a belt speed controller, which is configured to control a        speed of the internal conveyer, which can include a plurality of        oven level conveyers, such that a transit time of pieces that        are passing through the oven; all connected via    -   g) a data bus.

In a related aspect, the production system can further include a masamoisture sensor, which is configured to measure a moisture content ofmasa on the cooker conveyer; wherein the masa moisture sensor is areflection absorption moisture sensor.

In a related aspect, the production system can further include a chipmoisture sensor, which is configured to moisture content of the bakedpieces that are emitted from the oven.

In a related aspect, the production system can further include a lasersensor, which is configured to measure a surface height of the friedpieces that are emitted from the fryer on a fryer conveyer, such thatthe laser sensor obtains a continuous sequence of height measurements ata predetermined measuring rate; and a laser controller, which isconfigured to control the laser sensor, and can disable and enable thelaser sensor.

In a related aspect, the production system can further include a textureclassifier, which can be configured to analyze the continuous sequenceof height measurements from the laser sensor in order to calculate atexture classification of surfaces of the fried pieces that are emittedfrom the fryer on a fryer conveyer.

In a related aspect, the chip moisture sensor can be a time-domainreflectometry moisture sensor, which is configured to analyzepropagation of electromagnetic radiation to determine relativepermittivity.

In related aspects, additional chip moisture sensors can be positionedin other locations in the production line.

In a related aspect, the texture classifier can be configured tocalculate a fast Fourier transform on the continuous sequence of heightmeasurements in order to calculate a discrete Fourier transform therebyobtaining a frequency domain representation of the continuous sequence,which is correlated to a probability density function for thedistribution of blisters, which characterizes the rate of occurrence ofdifferent sizes of blisters, such that a frequency in the frequencydomain representation corresponds to: a wavelength, which corresponds toa blister diameter, wherein the frequency is correlated to a speed of afryer conveyer, and an amplitude, which measures the probability ofoccurrence.

In a related aspect, the texture classifier can be configured tocalculate a deviation density function as the calculated probabilitydensity function minus a target density function, such that the textureclassifier is configured to classify a product related to the continuoussequence as specification compliant, if the maximum value of thedeviation density function across the frequency domain is less than apredetermined acceptable deviation.

In a related aspect, the production control unit can further include afeedback controller, which can be configured to execute a first controlloop feedback calculation to optimize the temperature of the oven toreach a predetermined moisture target for moisture between the oven andthe fryer.

In a related aspect, the first control loop feedback algorithm can be aproportional-integral-derivative controller algorithm.

In a related aspect, the feedback controller can be further configuredto execute a second control loop feedback calculation to optimize thebelt speed of the oven to reach a predetermined moisture target formoisture between the oven and the fryer.

In a related aspect, the feedback controller can be configured toexecute the first and second control loop feedback calculations inparallel.

In a related aspect, the feedback controller is configured to storehistorical records for chip production, including:

-   -   a) a production result domain, comprising: surface        characteristics of chips emitted from the equalizer; and surface        characteristic of chips emitted from the fryer; and    -   b) a production parameter domain, including measurements of masa        moisture; oven temperature; oven transit time; equalizer        temperature; equalizer transit time; chip moisture; frying        temperature; and frying time.

In a related aspect, the feedback controller can be configured tocalculate a characteristic production function from the productionparameter domain to the production result domain, by executing afunction fitting algorithm to fit the characteristic production functionto the historical records for chip production.

In a related aspect, the function fitting algorithm can be an artificialneural network that is trained on the historical records.

In a related aspect, a method for tortilla and tortilla chip productioncontrol, can include some or all of:

-   -   a) Controlling moisture content of masa before pieces of the        masa enters an oven of a production line;    -   b) Measuring masa moisture, wherein a production control unit        can communicate with a masa moisture sensor to measure a        moisture content of masa on the cooker conveyer;    -   c) Controlling oven, wherein a transit time and a temperature of        the oven can be adjusted to control baking of the pieces;    -   d) Measuring chip moisture, wherein the production control unit        can communicate with a chip moisture sensor to measure a        moisture content of baked pieces that are emitted from the oven;    -   e) Measuring baked surfaces, wherein a surface height of baked        pieces that are emitted from the oven can be measured with a        laser sensor, such that the laser sensor obtains a continuous        sequence of height measurements;    -   f) Measuring fried surfaces, wherein a surface height of fried        pieces that are emitted from the fryer can be measured with a        laser sensor, such that the laser sensor obtains a continuous        sequence of height measurements;    -   g) Classifying baked surfaces, wherein a production control unit        can calculate a first texture classification of surfaces of the        baked pieces that are emitted from the oven;    -   h) Classifying fried surfaces, wherein a production control unit        can calculate a second texture classification of surfaces of the        fried pieces that are emitted from the fryer;    -   i) Optimizing oven temperature, wherein the production control        unit can execute a first control loop feedback calculation to        optimize the temperature of the oven to reach a predetermined        moisture target for moisture of the baked pieces that are        emitted from the oven.    -   j) Optimizing oven belt speed, wherein the production control        unit can execute a second control loop feedback calculation to        optimize the belt speed of the oven to reach a predetermined        moisture target for moisture of the baked pieces that are        emitted from the oven;    -   k) Storing historical records, wherein the feedback controller        can store historical records for chip production, including:        -   A production result domain, including surface            characteristics of chips emitted from the equalizer; and            surface characteristics of chips emitted from the fryer;        -   A production parameter domain, including measurement of masa            moisture; oven temperature; oven transit time; equalizer            temperature; equalizer transit time; chip moisture; frying            temperature; and frying time.    -   l) Characterizing historical records, wherein the feedback        controller can calculate a characteristic production function        from the production parameter domain to the production result        domain, by fitting or matching a non-linear or linear function        to the historical records for chip production, using well-known        methods for function fitting of multi-dimensional data samples.

There has thus been outlined, rather broadly, certain embodiments of theinvention in order that the detailed description thereof herein may bebetter understood, and in order that the present contribution to the artmay be better appreciated. There are, of course, additional embodimentsof the invention that will be described below and which will form thesubject matter of the claims appended hereto.

In this respect, before explaining at least one embodiment of theinvention in detail, it is to be understood that the invention is notlimited in its application to the details of construction and to thearrangements of the components set forth in the following description orillustrated in the drawings. The invention is capable of embodiments inaddition to those described and of being practiced and carried out invarious ways. In addition, it is to be understood that the phraseologyand terminology employed herein, as well as the abstract, are for thepurpose of description and should not be regarded as limiting.

As such, those skilled in the art will appreciate that the conceptionupon which this disclosure is based may readily be utilized as a basisfor the designing of other structures, methods and systems for carryingout the several purposes of the present invention. It is important,therefore, that the claims be regarded as including such equivalentconstructions insofar as they do not depart from the spirit and scope ofthe present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram illustrating a tortilla production system,according to an embodiment of the invention.

FIG. 2 is a schematic diagram illustrating a production control unit,according to an embodiment of the invention.

FIG. 3 is a flowchart illustrating steps that may be followed, inaccordance with one embodiment of a method or process of tortillaproduction control.

FIG. 4 is a schematic diagram illustrating an oven of a tortillaproduction system, according to an embodiment of the invention.

DETAILED DESCRIPTION

Before describing the invention in detail, it should be observed thatthe present invention resides primarily in a novel and non-obviouscombination of elements and process steps. So as not to obscure thedisclosure with details that will readily be apparent to those skilledin the art, certain conventional elements and steps have been presentedwith lesser detail, while the drawings and specification describe ingreater detail other elements and steps pertinent to understanding theinvention.

The following embodiments are not intended to define limits as to thestructure or method of the invention, but only to provide exemplaryconstructions. The embodiments are permissive rather than mandatory andillustrative rather than exhaustive.

In the following, we describe the structure of an embodiment of aproduction system 100 with reference to FIG. 1, in such manner that likereference numerals refer to like components throughout; a conventionthat we shall employ for the remainder of this specification.

In an embodiment, a production system 100 for moisture and texturedetection and control in tortilla and tortilla chip production caninclude at least one, a subset of, or all of:

-   -   a) a production line, including:        -   i. a cooker/grinder 112; which is configured to            -   1. receive a mixture of raw corn, water, and food-grade                lime, in the form of calcium oxide (quicklime) or                calcium hydroxide (hydrated lime);            -   2. cook the mixture, and optionally quench the cooked                mixture;            -   3. grind the mixture, thereby creating corn masa, a                traditional corn dough used for tortilla production;            -   4. optionally, quench the masa, wherein the                cooker/grinder is configured to rapidly cool the masa                down to about 68-72 degrees Celsius;            -   In related embodiment, the cooker/grinder 112 can                include a subsystem of corn holding hopper, a kettle for                cooking, soak tanks for soaking the cooked corn, a corn                washer, a mill/grinder, and a masa pump, all connected                via pipes and/or other conveyers;        -   ii. A sheeter/cutter 114, which is configured to:            -   1. receive the masa from the cooker/grinder 112, via a                cooker conveyer 113, which can be a pipe conveyer 113;            -   2. form a sheet of the masa, which is kneaded, extruded                and fed through sheeter rolls, to form a sheet;            -   3. cutting pieces from the sheet of masa, such that the                pieces are configured to be used for tortilla chips or                tortillas, and can be cut in at least one predetermined                shape;        -   iii. An oven 122, which is configured to receive the pieces            from the sheeter/cutter 114 via a sheeter conveyer 115, such            that the pieces pass through the oven 122 on an internal            conveyer, such that the pieces are baked when passing            through the oven 122. The oven 122 can be gas fired, and the            internal own conveyer can be arranged in multiple sections,            tiers, or levels, which for example can include three oven            levels arranged at different heights in the oven 122;        -   iv. An equalizer 124, which can also be called a proofer or            cooler, which is configured to receive the baked pieces from            the oven 122 via an oven conveyer 123, such that the            equalizer 124 is configured to cool the baked pieces;        -   v. A fryer 132, which is configured to receive the baked            pieces from the equalizer 124, via an equalizer conveyer            125, such that the fryer 132 is configured to fry the cooled            baked pieces;        -   vi. A cooler/packaging machine 134, which is configured to            receive the fried pieces from the fryer 132, via a fryer            conveyer 133, such that the cooler/packaging machine 134 is            configured to cool and pack the fried pieces;    -   b) A production control unit 150, which can be configured to        control components of the production line 110; and can further        include:        -   a. A masa moisture sensor 154, which is configured to            measure a moisture content of the corn masa that is emitted            from the cooker grinder 112;        -   b. A chip moisture sensor 162, which is configured to            measure a moisture content of the baked pieces that are            emitted from the oven 122;        -   c. A laser sensor 166, which is configured to measure a            surface height of the fried pieces that are emitted from the            fryer 132, such that the laser sensor 166 obtains a            continuous sequence of height measurements at a measuring            rate of up to 20 kHz or higher;

In related embodiments, the additional chip moisture sensors 162 can bepositioned in other locations of the production line to measure moisturecontent of chips in production, such that moisture can be measured afterbaking in the oven 122, after cooling in the equalizer 124; after fryingin the fryer 132; and/or after cooling and before packing in thecooler/packaging machine 134. The cooler/packaging machine 134 may beconfigured as a cooler component and a packaging machine, which areconnected by a cooler conveyer, such that a chip moisture sensor 162 canbe positioned to measure cooled chips on the cooler conveyer beforepackaging.

In conventional tortilla and tortilla chip production lines, moisturecontrol is performed at the masa stage, prior to baking and frying,using conventional reflection absorption moisture sensor technology.However, such sensors are not well suited for use on baked foodproducts, and are therefore not used in stages after baking. Due toabsence of available methods for accurate moisture detection, tortillaand tortilla chip production lines are therefore reliant on pre-bakingmoisture on-line analysis or lab based off-line analysis.

In a related embodiment, the production control unit 150 can beconfigured to execute a control loop feedback algorithm to stabilize amoisture reading from the chip moisture sensor 154 to reach a moistureset point, based on adjustment of the oven temperature, the oven beltspeed, or both. The control loop feedback algorithm can for example be aconventional PID control algorithm.

In a related embodiment, a laser sensor 164 can be mounted in a staticposition and configured to take continuous measurements of objectspassing by in a static point of the equalizer conveyer 125.

In a related embodiment, a laser sensor 166 can be mounted in a staticposition and configured to take continuous measurements of objectspassing by in a static point of the fryer conveyer 133. Alternatively,or additionally, in further related embodiments, a laser sensor 166 canbe mounted in a static position and configured to take continuousmeasurements of objects passing by in a static point of the ovenconveyer 123, and/or a cooler conveyer, after cooling in thecooler/packaging machine 134.

In a related embodiment, as shown in FIG. 4, an oven 122 can include:

-   -   a) a plurality of n oven levels 420 430, each including        -   i. an oven belt 428 438, which is configured to transport            pieces that are positioned on the oven belt 428 438;        -   ii. a plurality of m gas burners 421 424 431 434, which are            configured to bake the pieces that are transported on the            oven belt 428 438; and        -   iii. at least one temperature sensor 426 436.

In a related embodiment, as shown in FIG. 2, a production control unit150 can include:

-   -   b) A processor 202;    -   c) A non-transitory memory 204;    -   d) An input/output component 206;    -   e) A masa moisture sensor 154, which can be configured to        measure a moisture content of masa on the cooker conveyer 113;    -   f) A chip moisture sensor 162, which can be configured to        measure moisture content of the baked pieces that are emitted        from the oven 122;    -   g) A laser sensor 166, which can be configured to measure a        surface height of the fried pieces that are emitted from the        fryer 132, such that the laser sensor 166 obtains a continuous        sequence of height measurements at a measuring rate of up to 20        kHz or higher;    -   h) A laser controller 208, which can be configured to control        the laser sensor 166, and can disable and enable the laser        sensor 166;    -   i) A texture classifier 210, which can be configured to analyze        the continuous sequence of height measurements from the laser        sensor 166 in order to calculate a texture classification of        surfaces of the fried pieces that are emitted from the fryer        132;    -   j) A moisture controller 152, which can be configured to control        moisture content of masa in the cooker/grinder 112 by adjusting        a proportion of water in the mixture of raw corn, water, and        food-grade lime that is processed by the cooker/grinder 112;    -   k) A temperature controller 156, which can be configured to        communicate with the oven 122 to control a temperature profile        of the oven 122, for example by adjusting a gas supply to        burners in the oven or by adjusting electric power to electric        heating elements; and    -   l) A belt speed controller 158, which can be configured to        control a speed of the internal conveyer, which can include a        plurality of oven level conveyers, such that a transit time of        pieces that are passing through the oven 122 can be adjusted;        all connected via    -   m) A data bus 220.

In a further related embodiment, the temperature controller 156 can beconfigured to control temperatures for each level in the oven 122, orfor individual groupings of burners in the oven 122, such that controlof various temperatures and speeds of various belts determines thetemperature profile, wherein the temperature profile is defined as thetemperature history of components of the oven 122, including levels orcompartments.

In a further related embodiment, the belt speed controller 158, can beconfigured to control individual belt speeds for belts in each level orstage in the oven 122.

In a related embodiment, the masa moisture sensor 154 can be areflection absorption moisture sensor, such as for example an IR-3000NIR Moisture Gauge manufactured by Sensortech Systems, Inc.

In a related embodiment, the chip moisture sensor 162 can be atime-domain reflectometry moisture sensor, which analyzes propagation ofradar waves (i.e. electromagnetic radiation) to determine relativepermittivity (i.e. dielectric constant) and thereby determine moisturecontent. The chip moisture sensor 162 can for example be a Sono-Variomoisture probe manufactured by IMKO Micromodultechnik GmbH.

In a related embodiment, the texture classifier 210, can be configuredto calculate a Fast Fourier Transform on the continuous sequence ofheight measurements in order to calculate a discrete Fourier transformthereby obtaining a frequency domain representation of the continuoussequence, which is correlated to a probability density function for thedistribution of blisters, which characterizes the rate of occurrence ofdifferent sizes of blisters, such that a frequency in the frequencydomain representation corresponds to:

-   -   a) a wavelength, which corresponds to a blister diameter,        wherein the frequency is correlated to the speed of the fryer        conveyer 133, and    -   b) an amplitude, which measures the probability of occurrence.

In a further related embodiment, the texture classifier 210, can beconfigured to remove/filter out irrelevant parts of the continuoussequence, prior to calculating the Fast Fourier Transform, which caninclude removing:

-   -   a) Low frequency signals, which correspond to a conveyer 123 125        133 surface, such that signals below a predetermined        low-frequency threshold are removed. The low-frequency threshold        can be a calibrated value; and    -   b) High frequency signals, which can correspond to a chip edge,        or can be associated with other artifacts not related to a chip        surface, such that signals above a predetermined high-frequency        threshold are removed. The high-frequency threshold can be a        calibrated value;    -   whereby the remaining signal is strongly correlated with        surfaces of chips that are transported on the conveyer 123 125        133.

In a further related embodiment, the texture classifier 210, can beconfigured to calculate a deviation density function as the calculatedprobability density function minus a target density function, such thatthe texture classifier is configured to classify products related to thecontinuous sequence as “on spec” if the maximum value of the deviationdensity function across the frequency domain is less than apredetermined acceptable deviation. A specific target density functioncan be associated with different types of products and be part of theproduction recipe in a supervisory control system for the specificproduct.

In an alternative related embodiment, the texture classifier 210, can beconfigured to perform a circular curve fitting regression on thecontinuous sequence of height measurements, for example by a circularleast square curve fitting method, or other well-known circle curvefitting methods, in order to characterize and count blisters accordingto a size distribution. A potential blister would be located using achange in positive to negative derivative of the position data, tolocate edges, and a circular regression analysis would be run for datapoints in that area. If a circle is detected at a correlation factorhigher than some selected threshold, then the instance of the circlewould be recorded against a histogram or bin type distribution. Asimilar algorithm could be executed for fitting ellipse shaped blisters,using similar methods for curve fitting of ellipses, to also match aration of long axis to short axis.

In a related embodiment, the texture classifier 210 can be implementedwith a high-speed signal processor, which can be FPGA based, or it canbe implemented as a combination of software and a high speed signalprocessor, or purely in software.

In a further related embodiment, the high-speed signal processor of thetexture classifier 210 can be configured to filter out significant noisefrom variation in thickness, movement and vibration of the conveyor,etc.

In another related embodiment, the production control unit 150 canfurther include:

-   -   a) a feedback controller 212, which can be configured to execute        a first control loop feedback calculation to optimize the        temperature profile of the oven 122 to reach a predetermined        moisture target for moisture content of the baked pieces that        are emitted from the oven 122, wherein the temperature profile        includes a temperature for each level 420 430 of the oven 122,        wherein each temperature can be optimized by a separate control        loop feedback calculation.

In a further related embodiment, the first control loop feedbackalgorithm of the feedback controller can be aproportional-integral-derivative controller algorithm, such that:

${u_{temp}(t)} = {{K_{p}{e_{temp}(t)}} + {K_{i}{\int{{e_{temp}(t)}{t}}}} + {K_{d}{\frac{}{t}\left\lbrack {e_{temp}(t)} \right\rbrack}}}$

where

-   -   u_(temp) (t) is a control variable for control of the        temperature of the oven;    -   e_(temp) (t) is an error term for the current moisture as        compared to a moisture set point, i.e. e_(temp) (t)=SP(t)−PV(t);    -   K_(p), K_(i), and K_(d) are tuning coefficients for respectively        the proportional, integral, and derivative terms.

In a further related embodiment, temperature of the oven 122 can becontrolled using systems, devices and methods disclosed in U.S.Non-Provisional patent application Ser. No. 14/964,193, filed Dec. 9,2015, titled “System, device, and method for oven temperature control intortilla and tortilla chip production”, which is incorporated herein byreference in its entirety, under 37 CFR §1.57. The relationship betweenmoisture and temperature is highly non-linear and dependent on initialmoisture, variable masa properties, and transit time. A traditionalproportional-integral-derivative controller algorithm is therefore onlyfully effective for use in the cooker/grinder 112 stage.

In yet a related embodiment, the feedback controller 212, can further beconfigured to execute a second control loop feedback calculation tooptimize a belt speed profile of the oven to reach a predeterminedmoisture target for moisture content of the baked pieces that areemitted from the oven 122, wherein the belt speed profile includes abelt speed for a belt 428 438 in each level 420 430 of the oven 122,wherein each belt speed can be optimized by a separate control loopfeedback calculation.

In further related embodiments, the feedback controller 212 can beconfigured to execute the first and second control loop feedbackcalculations independently/separately, in sequence, and/or in parallel.In this relation, for a specific masa recipe, production of an optimaland consistent tortilla chip may include stabilizing to predeterminedset points for masa moisture and oven temperature.

In related embodiments, a plurality of combinations of temperature andbelt speed profiles may produce the desired moisture as measured acrossthe entire chip, such that an optimum distribution of moisture throughthe chip produces the desired texture with the appropriate overallmoisture content to ensure stable shelf life of the resulting product.

In a further related embodiment, the feedback controller 212 can beconfigured to store historical records for chip production, including:

-   -   a) A production result domain, including:        -   i. the surface characteristics of chips emitted from the            equalizer 124;        -   ii. surface characteristic of chips emitted from the fryer            132;    -   b) A production parameter domain, including measurement of        -   iii. masa moisture;        -   iv. oven temperature for each level 420 430 of the oven 122;        -   v. oven transit time for each level 420 430 of the oven 122;        -   vi. equalizer temperature;        -   vii. equalizer transit time;        -   viii. chip moisture;        -   ix. fryer inlet temperature;        -   x. fryer outlet temperature;        -   xi. fryer oil flow; and        -   xii. frying time.

In a yet further related embodiment, the feedback controller can beconfigured to calculate a characteristic production function from theproduction parameter domain to the production result domain, by fittingor matching a non-linear or linear function to the historical recordsfor chip production, using well-known methods for function fitting ofmulti-dimensional data samples. Such function fitting can for example becalculated by using a plurality of well-known methods from the areas ofmachine learning, function approximation, and curve fitting, including:

-   -   a) Calculating the characteristic production function by        configuring the characteristic production function as an        artificial neural network, and training the artificial neural        network on the historical records;    -   b) Calculating the characteristic production function by        least-square function approximation to match historical records.

In an embodiment, as illustrated in FIG. 3, a method for tortilla andtortilla chip production control 300, can include at least one, asubset, or all of:

-   -   a) Controlling moisture content 302, wherein moisture content of        masa is adjusted before pieces of the masa enters an oven 122 of        a production line 110, which can be done during a grinding        process in the cooker/grinder 112;    -   b) Measuring masa moisture 304, wherein a production control        unit 150 communicates with a masa moisture sensor 154, to        measure a moisture content of masa on the cooker conveyer 113;    -   c) Controlling oven 306, wherein a transit time and a        temperature of the oven 122 are adjusted to control baking of        the pieces;    -   d) Measuring chip moisture 308, wherein a production control        unit 150 communicates with a chip moisture sensor 162 to measure        a moisture content of baked pieces that are emitted from the        oven 122;    -   e) Measuring baked surfaces 310, wherein a surface height of        baked pieces that are emitted from the oven 122 are measured        with a first laser sensor 164, such that the first laser sensor        164 obtains a continuous sequence of height measurements at a        measuring rate of up to 20 kHz or higher;    -   f) Measuring fried surfaces 312, wherein a surface height of        fried pieces that are emitted from the fryer 132 are measured        with a second laser sensor 166, such that the second laser        sensor 166 obtains a continuous sequence of height measurements        at a measuring rate of up to 20 kHz or higher;    -   g) Classifying baked surfaces 314, wherein a production control        unit 150 calculates a first texture classification of surfaces        of the baked pieces that are emitted from the oven 122;    -   h) Classifying fried surfaces 316, wherein a production control        unit 150 calculates a second texture classification of surfaces        of the fried pieces that are emitted from the fryer 132;    -   i) Optimizing oven temperature 318, wherein the production        control unit 150 executes a first control loop feedback        calculation to optimize the temperature profile of the oven 122        to reach a predetermined moisture target for moisture of the        baked pieces that are emitted from the oven 122.    -   j) Optimizing oven belt speed 320, wherein the production        control unit 150 executes a second control loop feedback        calculation to optimize the belt speed profile of the oven 122        to reach a predetermined moisture target for moisture of the        baked pieces that are emitted from the oven 122;    -   k) Storing historical records 322, wherein the feedback        controller 212 stores historical records for chip production,        including:        -   i. A production result domain, including:            -   1. surface characteristics of chips emitted from the                equalizer 124;            -   2. surface characteristics of chips emitted from the                fryer 132;        -   ii. A production parameter domain, including measurement of:            -   1. masa moisture;            -   2. oven temperature;            -   3. oven transit time;            -   4. equalizer temperature;            -   5. equalizer transit time;            -   6. chip moisture;            -   7. frying temperature; and            -   8. frying time.    -   l) Characterizing historical records 324, wherein the feedback        controller 212 calculates a characteristic production function        from the production parameter domain to the production result        domain, by fitting or matching a non-linear or linear function        to the historical records for chip production, using well-known        methods for function fitting of multi-dimensional data samples.

FIGS. 1, 2, and 3 are block diagrams and flowcharts, methods, devices,systems, apparatuses, and computer program products according to variousembodiments of the present invention. It shall be understood that eachblock or step of the block diagram, flowchart and control flowillustrations, and combinations of blocks in the block diagram,flowchart and control flow illustrations, can be implemented by computerprogram instructions or other means. Although computer programinstructions are discussed, an apparatus or system according to thepresent invention can include other means, such as hardware or somecombination of hardware and software, including one or more processorsor controllers, for performing the disclosed functions.

In this regard, FIGS. 1, 2, and 3 depict the computer devices of variousembodiments, each containing several of the key components of ageneral-purpose computer by which an embodiment of the present inventionmay be implemented. Those of ordinary skill in the art will appreciatethat a computer can include many components. However, it is notnecessary that all of these generally conventional components be shownin order to disclose an illustrative embodiment for practicing theinvention. The general-purpose computer can include a processing unitand a system memory, which may include various forms of non-transitorystorage media such as random access memory (RAM) and read-only memory(ROM). The computer also may include nonvolatile storage memory, such asa hard disk drive, where additional data can be stored.

It shall be understood that the above-mentioned components of theproduction control unit 150 are to be interpreted in the most generalmanner.

For example, the processor 202 can include a single physicalmicroprocessor or microcontroller, a cluster of processors, a datacenteror a cluster of datacenters, a computing cloud service, and the like.

In a further example, the non-transitory memory 204 can include variousforms of non-transitory storage media, including random access memoryand other forms of dynamic storage, and hard disks, hard disk clusters,cloud storage services, and other forms of long-term storage. Similarly,the input/output 206 can include a plurality of well-known input/outputdevices, such as screens, keyboards, pointing devices, motion trackers,communication ports, and so forth.

Furthermore, it shall be understood that the production control unit 150can include a number of other components that are well known in the artof general computer devices, and therefore shall not be furtherdescribed herein. This can include system access to common functions andhardware, such as for example via operating system layers such asWindows, Linux, and similar operating system software, but can alsoinclude configurations wherein application services are executingdirectly on server hardware or via a hardware abstraction layer otherthan a complete operating system.

An embodiment of the present invention can also include one or moreinput or output components, such as a mouse, keyboard, monitor, and thelike. A display can be provided for viewing text and graphical data, aswell as a user interface to allow a user to request specific operations.Furthermore, an embodiment of the present invention may be connected toone or more remote computers via a network interface. The connection maybe over a local area network (LAN) wide area network (WAN), and caninclude all of the necessary circuitry for such a connection.

In a related embodiment, the production control unit 150 can communicatewith the production line 110 over a network, which can include thegeneral Internet, a Wide Area Network or a Local Area Network, oranother form of communication network, transmitted on wired or wirelessconnections. Wireless networks can for example include Ethernet, Wi-Fi,Bluetooth, ZigBee, and NFC. The communication can be transferred via asecure, encrypted communication protocol.

Typically, computer program instructions may be loaded onto the computeror other general-purpose programmable machine to produce a specializedmachine, such that the instructions that execute on the computer orother programmable machine create means for implementing the functionsspecified in the block diagrams, schematic diagrams or flowcharts. Suchcomputer program instructions may also be stored in a computer-readablemedium that when loaded into a computer or other programmable machinecan direct the machine to function in a particular manner, such that theinstructions stored in the computer-readable medium produce an articleof manufacture including instruction means that implement the functionspecified in the block diagrams, schematic diagrams or flowcharts.

In addition, the computer program instructions may be loaded into acomputer or other programmable machine to cause a series of operationalsteps to be performed by the computer or other programmable machine toproduce a computer-implemented process, such that the instructions thatexecute on the computer or other programmable machine provide steps forimplementing the functions specified in the block diagram, schematicdiagram, flowchart block or step.

Accordingly, blocks or steps of the block diagram, flowchart or controlflow illustrations support combinations of means for performing thespecified functions, combinations of steps for performing the specifiedfunctions and program instruction means for performing the specifiedfunctions. It will also be understood that each block or step of theblock diagrams, schematic diagrams or flowcharts, as well ascombinations of blocks or steps, can be implemented by special purposehardware-based computer systems, or combinations of special purposehardware and computer instructions, that perform the specified functionsor steps.

As an example, provided for purposes of illustration only, a data inputsoftware tool of a search engine application can be a representativemeans for receiving a query including one or more search terms. Similarsoftware tools of applications, or implementations of embodiments of thepresent invention, can be means for performing the specified functions.For example, an embodiment of the present invention may include computersoftware for interfacing a processing element with a user-controlledinput device, such as a mouse, keyboard, touch screen display, scanner,or the like. Similarly, an output of an embodiment of the presentinvention may include, for example, a combination of display software,video card hardware, and display hardware. A processing element mayinclude, for example, a controller or microprocessor, such as a centralprocessing unit (CPU), arithmetic logic unit (ALU), or control unit.

Here has thus been described a multitude of embodiments of theproduction system 100, and devices, components, and methods relatedthereto, which can be employed in numerous modes of usage.

The many features and advantages of the invention are apparent from thedetailed specification, and thus, it is intended by the appended claimsto cover all such features and advantages of the invention, which fallwithin the true spirit and scope of the invention.

Many such alternative configurations are readily apparent, and should beconsidered fully included in this specification and the claims appendedhereto. Accordingly, since numerous modifications and variations willreadily occur to those skilled in the art, it is not desired to limitthe invention to the exact construction and operation illustrated anddescribed, and thus, all suitable modifications and equivalents may beresorted to, falling within the scope of the invention.

What is claimed is:
 1. A production system for moisture and texturedetection and control in tortilla chip production, comprising: a) aproduction line, comprising: an oven, which is configured to receivepieces of a masa from a sheeter/cutter, via a sheeter conveyer, suchthat the pieces pass through the oven on an internal conveyer, such thatthe pieces are baked when passing through the oven; and b) a productioncontrol unit, which is configured to control components of theproduction line, the production control unit comprising: a chip moisturesensor, which is configured to measure a moisture content of the bakedpieces that are emitted from the oven; and a laser sensor, which isconfigured to measure a surface height of the fried pieces that areemitted from the fryer, such that the laser sensor obtains a continuoussequence of height measurements at a predetermined measuring rate. 2.The production system of claim 1, wherein a) the production line furthercomprises: an equalizer, which is configured to receive the baked piecesfrom the oven, via an oven conveyer, such that the equalizer isconfigured to cool the baked pieces; and a fryer, which is configured toreceive the baked pieces from the equalizer, via an equalizer conveyer,such that the fryer is configured to fry the cooled baked pieces; and b)the production control unit further comprises: a laser sensor, which isconfigured to measure a surface height of the fried pieces that areemitted from the fryer, such that the laser sensor obtains a continuoussequence of height measurements at a predetermined measuring rate. 3.The production system of claim 1, wherein the production control unitfurther comprises: a) a processor; b) a non-transitory memory; c) aninput/output component; d) a moisture controller, which is configured tocontrol moisture content of the masa that is produced by acooker/grinder by adjusting a proportion of water in a mixture of rawcorn, water, and food-grade lime that is processed by thecooker/grinder; e) a temperature controller, which is configured tocommunicate with the oven to control a temperature profile of the oven;and f) a belt speed controller, which is configured to control a speedof the internal conveyer, such that a transit time of pieces that arepassing through the oven is adjustable; all connected via g) a data bus.4. The production system of claim 3, further comprising: a masa moisturesensor, which is configured to measure a moisture content of masa in thecooker conveyer; wherein the masa moisture sensor is a reflectionabsorption moisture sensor.
 5. The production system of claim 3, furthercomprising: a chip moisture sensor, which is configured to moisturecontent of the baked pieces that are emitted from the oven.
 6. Theproduction system of claim 3, further comprising: a) a laser sensor,which is configured to measure a surface height of the fried pieces thatare emitted from the fryer on a fryer conveyer, such that the lasersensor obtains a continuous sequence of height measurements at apredetermined measuring rate; and b) a laser controller, which isconfigured to control the laser sensor, and can disable and enable thelaser sensor.
 7. The production system of claim 3, further comprising: atexture classifier, which is configured to analyze the continuoussequence of height measurements from the laser sensor in order tocalculate a texture classification of surfaces of the fried pieces thatare emitted from the fryer on a fryer conveyer.
 8. The production systemof claim 3, wherein the chip moisture sensor is a time-domainreflectometry moisture sensor, which is configured to analyzepropagation of electromagnetic radiation to determine relativepermittivity.
 9. The production system of claim 3, wherein the textureclassifier is configured to calculate a fast Fourier transform on thecontinuous sequence of height measurements in order to calculate adiscrete Fourier transform thereby obtaining a frequency domainrepresentation of the continuous sequence, which is correlated to aprobability density function for the distribution of blisters, whichcharacterizes the rate of occurrence of different sizes of blisters,such that a frequency in the frequency domain representation correspondsto: a) a wavelength, which corresponds to a blister diameter, whereinthe frequency is correlated to a speed of a fryer conveyer, and b) anamplitude, which measures the probability of occurrence.
 10. Theproduction system of claim 6, wherein the texture classifier isconfigured to calculate a deviation density function as the calculatedprobability density function minus a target density function, such thatthe texture classifier is configured to classify a product related tothe continuous sequence as specification compliant, if the maximum valueof the deviation density function across the frequency domain is lessthan a predetermined acceptable deviation.
 11. The production system ofclaim 3, wherein the production control unit further comprises: afeedback controller, which is configured to execute a first control loopfeedback calculation to optimize the temperature of the oven to reach apredetermined moisture target for moisture between the oven and thefryer.
 12. The production system of claim 8, wherein the first controlloop feedback algorithm is a proportional-integral-derivative controlleralgorithm.
 13. The production system of claim 8, wherein the feedbackcontroller is further configured to execute a second control loopfeedback calculation to optimize the belt speed of the oven to reach apredetermined moisture target for moisture between the oven and thefryer.
 14. The production system of claim 3, wherein the feedbackcontroller is configured to execute the first and second control loopfeedback calculations in parallel.
 15. The production system of claim 3,wherein the feedback controller is configured to store historicalrecords for chip production, comprising: a) a production result domain,comprising: surface characteristics of chips emitted from the equalizer;and surface characteristic of chips emitted from the fryer; and b) aproduction parameter domain, comprising measurements of masa moisture;oven temperature; oven transit time; equalizer temperature; equalizertransit time; chip moisture; frying temperature; and frying time. 16.The production system of claim 12, wherein the feedback controller isconfigured to calculate a characteristic production function from theproduction parameter domain to the production result domain, byexecuting a function fitting algorithm to fit the characteristicproduction function to the historical records for chip production. 17.The production system of claim 12, wherein the function fittingalgorithm is an artificial neural network that is trained on thehistorical records.
 18. A method for production control for productionof tortillas and tortilla chips, comprising: a) controlling moisturecontent, wherein moisture content of a masa is adjusted before pieces ofthe masa enters an oven of a production line; b) measuring masamoisture, wherein a production control unit communicates with a masamoisture sensor to measure a moisture content of masa on the cookerconveyer; c) controlling oven, wherein a transit time and a temperatureof the oven are adjusted to control baking of the pieces; and d)measuring chip moisture, wherein a production control unit communicateswith a chip moisture sensor to measure a moisture content of bakedpieces that are emitted from the oven.
 19. The method for productioncontrol of claim 18, further comprising: a) measuring baked surfaces,wherein a surface height of baked pieces that are emitted from the ovenare measured with a first laser sensor, such that the first laser sensorobtains a first continuous sequence of height measurements; and b)measuring fried surfaces, wherein a surface height of fried pieces thatare emitted from a fryer are measured with a second laser sensor, suchthat the second laser sensor obtains a second continuous sequence ofheight measurements.
 20. The method for production control of claim 19,further comprising: a) classifying baked surface, wherein a productioncontrol unit calculates a first texture classification of surfaces ofthe baked pieces that are emitted from the oven, via processing of thefirst continuous sequence of height measurements; and b) classifyingfried surface, wherein the production control unit calculates a secondtexture classification of surfaces of the fried pieces that are emittedfrom the fryer, via processing of the second continuous sequence ofheight measurements.
 21. The method for production control of claim 18,further comprising: optimizing oven temperature; wherein a productioncontrol unit executes a first control loop feedback calculation tooptimize the temperature profile of the oven to reach a predeterminedmoisture target for moisture of the baked pieces that are emitted fromthe oven.
 22. The method for production control of claim 18, furthercomprising: optimizing oven belt speed profile; wherein the productioncontrol unit executes a second control loop feedback calculation tooptimize the belt speed profile of the oven to reach a predeterminedmoisture target for moisture of the baked pieces that are emitted fromthe oven.
 23. The method for production control of claim 18, furthercomprising: storing historical records, wherein the feedback controllerstores historical records for chip production, comprising: a productionresult domain, comprising: surface characteristics of chips emitted fromthe equalizer; and surface characteristics of chips emitted from thefryer; and a production parameter domain, including measurements of:masa moisture; oven temperature for each level of the oven; oven transittime for each level of the oven; equalizer temperature; equalizertransit time; chip moisture; fryer inlet temperature; fryer outlettemperature; fryer oil flow; and frying time.
 24. The method forproduction control of claim 18, further comprising: calculating acharacteristic production function, wherein a feedback controllercalculates a characteristic production function as a mapping from theproduction parameter domain to the production result domain, byexecuting a function fitting algorithm to fit the characteristicproduction function to the historical records for chip production. 25.The method for production control of claim 24, wherein the functionfitting algorithm is an artificial neural network that is trained on thehistorical records.
 26. The method for production control of claim 18,wherein the chip moisture sensor is a time-domain reflectometry moisturesensor, which is configured to analyze propagation of electromagneticradiation to determine relative permittivity.
 27. The method forproduction control of claim 20, wherein the first and second textureclassifications are calculated by performing a fast Fourier transform onrespectively the first and second continuous sequences of heightmeasurements in order to calculate a discrete Fourier transform therebyobtaining a frequency domain representation of the continuous sequence,which is correlated to a probability density function for thedistribution of blisters, which characterizes the rate of occurrence ofdifferent sizes of blisters, such that a frequency in the frequencydomain representation corresponds to: a) a wavelength, which correspondsto a blister diameter, wherein the frequency is correlated to a speed ofa fryer conveyer, and b) an amplitude, which measures the probability ofoccurrence.
 28. The method for production control of claim 21, whereinthe first control loop feedback algorithm is aproportional-integral-derivative controller algorithm.